
Warfarin, a vitamin K antagonist, has been established as an anticoagulant treatment option for more than 60 years. When used appropriately, warfarin is effective in stroke prevention, reducing the risk of AF-related stroke by 64%.1
Warfarin has a narrow therapeutic window and multiple food and drug interactions, necessitating close monitoring of the drug’s effect on a patient through the international normalised ratio (INR) blood test. The effect of warfarin is strongly linked to the level of INR.
The self-monitoring of INR is an option for motivated patients on long-term warfarin treatment or those supported by a carer to monitor for them. Patient self-testing and self-management can improve anticoagulation control. Some studies have shown a statistically significant reduction in thromboembolic events for patients testing their own INRs compared with standard care, and a halving of the risk of mortality in participants with artificial heart valves.
Self-monitoring utilises a handheld device and a drop of blood taken from a finger prick test to measure the INR. In September 2014, NICE recommended the increased use of self-monitoring for appropriate patients on warfarin and approved the use of a point-of-care test (POCT) device.2
The evidence for self-monitoring is
robust and is set out in depth within the NICE guidance. In most studies reviewed within the guidance, there was no significant difference between self-monitoring (and self-management) and standard care and adherence was not found to be problematic.

Featured Resources
Pan-London information on patient self monitoring Link
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Innovation Agency Case Study – Warfarin Patients Self-Monitoring
Patients in East Lancashire are using technology and an app to monitor their atrial fibrillation (AF) at home. Around 200 people are ... read more